First of all the bad news: there are two different types of passive
a) one is focussing on the process itself
b) one is focussing more on the result on the state of something.

The process passive is formed with a conjugated form of werden and the perfect participle of the verb.

present       ich werde gerufen I am called   du wirst gerufen   you are called   er / sie / es wird gerufen   he, she, it is called   wir werden gerufen   we are called   ihr werdet gerufen   you are called   sie werden gerufen   they are called   Imperfect       ich wurde gerufen I was called   du wurdest gerufen   you were called   er / sie / es wurde gerufen   he, she, it was called   wir wurden gerufen   we were called   ihr wurdet gerufen   you were called   sie wurden gerufen   they were called   Present perfect     ich bin gerufen worden I have been called   du bist gerufen worden   you have been called   er / sie / es ist gerufen worden   he, she, it has been called   wir sind gerufen worden   we have been called   ihr seid gerufen worden   you have been called   sie sind gerufen worden   they have been called   Past perfect     ich war gerufen worden I had been called   du warst gerufen worden   you had been called   er / sie / es war gerufen worden   he, she, it had been called   wir waren gerufen worden   we had been called   ihr wart gerufen worden   you had been called   sie waren gerufen worden   she had been called

Examples   Die Leute wurden gefangen genommen. The people were caught (and send to prison).   Das Auto war repariert worden. The car had been repaired.   Die Autos waren repariert worden. The cars had been repaired.   Die Maschine war überprüft worden. The machine had been checked.